\documentclass[ solutions, hidewarning, singlenumbering, nopagenumber ]{../../resources/ormc_handout} \usepackage{../../resources/macros} % x,y,scale,style \def\ttt#1#2#3#4{ \draw[#4] (#1, #2+#3) -- (#1+#3+#3+#3, #2+#3); \draw[#4] (#1, #2+#3+#3) -- (#1+#3+#3+#3, #2+#3+#3); \draw[#4] (#1+#3, #2) -- (#1+#3, #2+#3+#3+#3); \draw[#4] (#1+#3+#3, #2) -- (#1+#3+#3, #2+#3+#3+#3); } \title{Warm-Up: Wild Tic-Tac-Toe} \subtitle{Prepared by \githref{Mark} on \today.} \begin{document} \maketitle \problem{} In wild tic-tac-toe, players may place either an X or O on each move. The player that first completes a row of any three symbols wins. Show that the first player always has a winning strategy. \vfill \begin{center} \begin{tikzpicture}[scale=0.60] \ttt{0}{0}{2}{line width=0.3mm} \ttt{7}{0}{2}{line width=0.3mm} \ttt{14}{0}{2}{line width=0.3mm} \ttt{0}{7}{2}{line width=0.3mm} \ttt{7}{7}{2}{line width=0.3mm} \ttt{14}{7}{2}{line width=0.3mm} \end{tikzpicture} \end{center} \vfill \problem{} Now, say the first player to complete a row loses. Who has a winning strategy now? \vfill \begin{center} \begin{tikzpicture}[scale=0.60] \ttt{0}{0}{2}{line width=0.3mm} \ttt{7}{0}{2}{line width=0.3mm} \ttt{14}{0}{2}{line width=0.3mm} \ttt{0}{7}{2}{line width=0.3mm} \ttt{7}{7}{2}{line width=0.3mm} \ttt{14}{7}{2}{line width=0.3mm} \end{tikzpicture} \end{center} \vfill \pagebreak \end{document}